E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 05-11-2015, 10:50 PM   #1
iStagl
Registered User
 
Join Date: Aug 2014
Location: Lowell, IN
Posts: 55
My Ride: 2001 330Ci "sport"
Rebuilding A Head...

So, I finally sorted out the misfire. I decided to change the spark plugs so I went out and bought OEM FGR7DQP Bosch plugs and did a compression check at the same time. I did find that there were crappy autolite plugs in the motor when I removed them.

During the compression check the first 5 cylinders hit 180 within three compression strokes. Cylinder 6 only hit ~70 by the third, and by the eighth it wouldn't go any more than 139. I have not done a wet compression check to see if it is the rings or the valve train, but I am pretty convinced it's a burned valve due to the lean codes and cylinder 6 misfire with fuel cutoff that have been fighting me since I bought the car.

My question is, is it worth replacing ALL of the valves in the head, intake and exhaust, for every cylinder? That, and replacing the lifters? If so, are there are any aftermarket valves or lifters I should install, seeing that this would be a great time to possibly do so, or would it best to stick with OEM? I'm doing the best job I can to keep quality OEM parts on this car seeing how they seem to reject cheaper alternatives, depending on the part.

This is also a great time to rebuild my VANOS system, seeing as it has been making some noise as well. I've got a few questions on that, also.

Last edited by iStagl; 05-11-2015 at 10:52 PM.
iStagl is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 05-12-2015, 05:53 AM   #2
Poolman
Registered User
 
Join Date: Jan 2015
Location: Virginia
Posts: 101
My Ride: 525 BMW
Before doing the head work, I would try a piston soak and see if you might have stuck piston rings in that cylinder. AC Delco Upper Engine Cleaner, you can buy the stuff at you local Chevy dealer. Take out # 6 plug, turn the engine to where that cylinder is down in the hole, away from top dead center,then jack the passenger side of the car up until the head of the engine looks level. Pour about 2 OZ's of the cleaner in, then let it sit for 24 hours. You will need to blow the rest of the liquid out before trying to start the car. I just turned the engine over with the key and shot it out of the cylinder, then used a vacuum pump to pull what was left out. Warning, it's going to smoke like hell for a short time when it's first cranked, Don't do this isn't a parking garage, gotta be outside for this one. Link

I had oil consumption problems and tried the above,it has seemed to help me greatly, but will back that up with more detail with findings at a later date. To add, the engine was going through a qt every 1000 miles, after doing the above, it's been almost 2000 miles , and my check engine oil light hasn't come on as of yet...
Poolman is offline   Reply With Quote
Old 05-12-2015, 06:03 AM   #3
Loaded325i
Registered User
 
Join Date: Aug 2011
Location: oregon
Posts: 403
My Ride: bmw 325i
You really need to do a leak down test to find exactly where the problem is coming from. If it's a burned exhaust valve you might be able to save it by replacing just that valve. You don't need to replace the ones that are okay. You could probably lap the valves so they seal better since you would be doing that to number 6 anyways. But if you discover the seat on cylinder 6 exhaust is burned severely you might be looking for a new seat cut into the head as well.

I've seen where there was a problem with the ring and caused low compression in a single cylinder.. So that's why I say you need to do a leakdown. Yeah, you could put oil down the cylinder but that doesn't tell you if your leaking compression through which valve. It doesn't say if you have a headgasket issue either. In fact most people I know don't even use a compression guage if there's engine trouble, they just go straight for the fruit and want to know where the loss is with a leak down.

The hydrolic lifters can be soaked in kerosene or diesel fuel that will clean them out.

A lot of people here have changed their vanos seals using the Beisan (I think that's how you spell it) kit with success. The rattling can be fixed with a new anti rattle.

I'm sure once u have the head off you will find out why it was running lean just don't forget to change or clean the fuel injector.

Also be vary careful removing the camshafts...They're hollow and will break. You need to make sure whatever valves that are loaded those caps are the last to come off and that the pressure is released in uniform with the others.

I wish I could reply with more specific examples but honestly I've never tore this engine apart other than just doing a headgasket and nothing else.
__________________
A mechanical hobbyist and car enthusiast
1971 Datsun 240z Devil Z red
1999 740il Titanium Silver
2004 BMW 325i CW,PP and Sports Package
1996 toyota avalon-263,000-Sold
2003 Lexus Is300-Sold
2000 Acura TL-Sold
2000 Accord 5 speed-Sold
Loaded325i is offline   Reply With Quote
Old 05-12-2015, 11:02 AM   #4
David F
Registered User
 
Join Date: Jul 2009
Location: Austin, TX
Posts: 523
My Ride: 323i, 740iL, 633CSi
If you end up needing to rebuild the head, give Brooks Elliot a call. He recently rebuilt my head and does outstanding work (it is all he does and he has the high dollar equipment to do it right). No, you don't need to replace the valves (unless damaged beyond repair). Brooks will regrind the valves and seat for virtually perfect sealing. Cost is reasonable ($400 or so probably).

http://www.austincylinderhead.com/

Also, if you end up pulling the head, you should consider Time-serting all the head bolt holes. Most would say only necessary to do if the head was warped. I say the aluminum threads are the weak link and may not handle multiple torque to yield cycles of the head bolts. Adds to the cost, but if a bolt hole fails, you end up buying a new gasket, waiting for the Time-sert tool and starting over.

Last edited by David F; 05-12-2015 at 11:05 AM.
David F is offline   Reply With Quote
Old 05-12-2015, 12:00 PM   #5
Dave1027
Registered User
 
Join Date: Jan 2013
Location: California
Posts: 1,355
My Ride: '06 IR 330ci zhp
Quote:
Originally Posted by Poolman View Post
I had oil consumption problems and tried the above,it has seemed to help me greatly, but will back that up with more detail with findings at a later date. To add, the engine was going through a qt every 1000 miles, after doing the above, it's been almost 2000 miles , and my check engine oil light hasn't come on as of yet...
You should do the 02Pilot mod. It might eliminate the rest of your oil burning and it's super easy to do.
Dave1027 is offline   Reply With Quote
Old 05-12-2015, 12:17 PM   #6
Poolman
Registered User
 
Join Date: Jan 2015
Location: Virginia
Posts: 101
My Ride: 525 BMW
Hmm, What is an 02 Pilot Mod? HAve to say , the piston soak did a good job. I've noticed , from the get go , that there is more vacuum created by doing this,,I state that because my brakes require less pressure to stop the car,,that and throttle responce is better also

Last edited by Poolman; 05-12-2015 at 12:21 PM.
Poolman is offline   Reply With Quote
Old 05-12-2015, 12:24 PM   #7
BMW-North
Registered User
 
Join Date: Feb 2008
Location: Self Banned User
Posts: 1,329
My Ride: Class of '15 Sucks
02Pilot Mod

http://www.bimmerforums.com/forum/sh...CV-replacement
__________________
BMW-North is offline   Reply With Quote
Old 05-12-2015, 12:27 PM   #8
Dave1027
Registered User
 
Join Date: Jan 2013
Location: California
Posts: 1,355
My Ride: '06 IR 330ci zhp
Quote:
Originally Posted by Poolman View Post
Hmm, What is an 02 Pilot Mod?
It's essentially adding a vacuum hose from the intake manifold to the CCV vacuum port. It increases crankcase vacuum but not near as much as a pcv/catch-can does.

Search Bimmerforums for it.
Dave1027 is offline   Reply With Quote
Old 05-12-2015, 12:46 PM   #9
Poolman
Registered User
 
Join Date: Jan 2015
Location: Virginia
Posts: 101
My Ride: 525 BMW
I did that years ago. That was the first thing I tried and others copied back about 7 years ago when I was battling oil usage with my first engine. It worked somewhat, but then started back. I then built my own oil catch can and used a PVC valve that was listed for a 76 Ford 6 cylinder. That worked great and the engine lasted about 150,000 miles with the CC added to it. The engine finally burnt a valve at 265,000 miles and I bought my current engine, which then had 52k miles on her. That engine worked great, no oil usage what so ever, for about 30,000 miles, then the CCV went south and it too started to use oil. So, I'm trying to find away to turn this around and still use the Factory CCV system. I may be on the right track,,but as stated in a previous post, time will tell. The 5 series now has 306,000 miles on her and is running great

Last edited by Poolman; 05-12-2015 at 12:48 PM.
Poolman is offline   Reply With Quote
Old 05-12-2015, 12:53 PM   #10
Dave1027
Registered User
 
Join Date: Jan 2013
Location: California
Posts: 1,355
My Ride: '06 IR 330ci zhp
Well I was thinking the magic formula was:

1. new ccv
2. piston soak
3. 02Pilot mod (this is to prevent having to do the piston soak again)
Dave1027 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 11:15 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use